Take the poha in a colander and wash it with running water once or twice.
Add it to the soaked rice.
Wash and soak the dal along with the methi dana for 5 hours.
Drain the water from the rice/poha as well as the dal.
Collect this water to add while grinding the batter.
Grind the dal and methi seeds to a fine paste consistency.
Add little water for ease grinding, but not too much.
Similarly, grind the soaked rice and poha to a slightly coarse consistency.
If the quantity is more as compared to the mixer jar size, grind in batches.
Mix urad dal and rice paste together and whisk well.
At this stage, sufficient water is to be added to get a semi-flowing consistency batter, just like dosas.
Ferment overnight by keeping covered in a warm place, without disturbing it.
Next morning add salt as per taste.
Now, to make paddus, add the chopped onions, green chillies, grated ginger, coriander leaves, hing and curry leaves.
Whisk it very well.
Heat an appam patra on low flame.
Add few drops of oil in each cavity.
Pour a heaped tablespoon of ready batter in each cavity.
Cover with a lid and let them cook for about 5 minutes.
When the base gets cooked to golden brown color, gently flip using a wooden skewer.
Remove when done and add in the next batch.
The center ones will cook faster so keep an eye on them and keep on removing the ones getting done.
Also, the paddus on cooking will shrink in size, so add the batter as per the size preferred.
Generally, the cavity should be filled about ¾th so as to make it easier to flip them.
Store any leftover batter in fridge and use as needed. Keeps good for a day.